In these days of giant oil tankers plying the seas there is an increasing danger of spillage of crude oil onto the surface of the oceans or inland waterways either through accident or mistake. There have already been enough such spillages for environmentalists to see that the damage to the ecology can be devastating when a spillage occurs and the spilled oil reaches shore. Additionally, the economic consequences of oil spillages are far-reaching, both from the standpoint of the losses incurred and the expense of attempting to recover the oil.
There have been many attempts at achieving an effective apparatus which will economically and efficiently recover oil following a spill. Such apparatus should be economical to produce, be readily transportable to the spill site, be relatively easy to operate and be efficient in its operation Several versions of oil skimming devices have been tried, such devices using a conveyor or other such apparatus to convey oil from the water surface upwardly to a waiting tank. Crude oil is extremely viscous and has the unwelcome property of sticking securely to almost anything it contacts. This leads to unending problems with conveyor-type recovery devices as they soon become clogged or bound by the oil itself.
One attempt at utilizing the properties of crude oil for recovery thereof is found in Canadian Pat. No. 998,624 issued Oct. 19, 1976 to Olsen. That patent teaches the utilization of a number of floating cells having openings adjacent the top through which an oil/water mixture passes by wave action into the cells. The mixture is pumped from each cell to a holding tank on board a ship or a barge. In the holding tank the oil floats to the top and uncontaminated water is returned to the sea through a ball float control valve by gravity. This device thus makes use of the lower specific gravity of the oil to achieve separation but it also has drawbacks. For example there is no control over the amount of oil/water mixture entering the cells as dependence is made on wave action to cause the mixture to enter the cells. Also the action of the cells and the subsequent pumping operation will result in unwanted emulsification of the oil in the water, making separation more difficult.